Electrofusion is a known technique for causing cell hybridization by the application of a high voltage electric field to cells suspended in an electrically conducting medium. The cells may be brought into mutual contact, for example to group into long chains often known as pearl chain formations, by means such as the addition to the suspension of polyethylene glycol, or dielectrophoresis or charge modification procedures.
Field strengths required for electrofusion of cells are of the order of 300 to 400 kV/m. At such field strengths, a major relevant factor in the known process, carried out on a batch basis in a fusion chamber, is conductive heating, so that a low conductivity non-physiological supporting medium has necessarily had to be employed to avoid heat damage to the cells, together with non-ionic osmotic compensation, for example achieved by the use of mannitol or sucrose as the suspension medium, because osmotic stress also gives rise to low cell viability.
It is a primary object of this invention to provide improved apparatus for the electrofusion of cells, which apparatus permits a physiologically normal medium, i.e. a medium which is ionically and osmotically normal for cells, to be employed, with a consequent substantial increase in cell viability.